HELP! Our boat won't go!!!

[QuadManiac]

Re: HELP! Our boat won't go!!!

Yes, I can buy water cooling of the prop and associated thrust bearings, etc. They are in a nearly infinite heat sink. If it IS friction related, I'd say the forward edge of the prop hub rubbing on the lower would be the best bet. But not the impeller or internal splines or most any other source of friction, as suggested in other posts.

I'm still gonna stand by my theory that it's not friction related; that it's something reducing the output power of at least one of the cylinders. Sorry I can't just tell you exactly what it is!

 

[maxum-mama]

Re: HELP! Our boat won't go!!!

Well crud. We took the carbs apart and one of the choke plates (?) was stuck. Thought that was the problem, but apparently it was the CAUSE of the problem... the stuck plate apparently caused the #1 to lose compression. All the others are fine, but that one only tested at about 50. Dang it. So now apparently our options are to buy a new powerhead (ouch), or try to get someone to sleeve it? I don't know...

Anyway thanks again, I guess we need to decide whether or not it's worth replacing the motor or just bagging the whole thing and hope we get something out of it in trade... ugh!!!

 

[Frank Acampora]

Re: HELP! Our boat won't go!!!

Just so hubby doesn't blame you: the scored cylinder is most likely not related to running aground. It is more likely caused by a lean run condition due to faulty carb.

You do NOT need to buy a new powerhead or resleeve the old one unless it is scored deeper than .020 (.040 overbore) Pistons have gone up in price but are still only about 125 each. If you don't mind doing the work, it is not a difficult repair. Not even really expensive.--Just time consuming.

Are you located within striking range of Philadelphia? If so, I can get you back on the water quickly. Send message to TonyonMemory@yahoo.com if you are interested.

 

[maxum-mama]

Re: HELP! Our boat won't go!!!

Well, that's reassuring... so it was just coincidence that it happened after I drove it! LOL

And it's even more encouraging that it might not cost us 3 grand to fix it! It'd just be changing the piston? Guess we'd better check on that... I know my husband is having a mechanic check on some stuff for us but I'm not sure what, or if they've called back.

We're over in Washington State, I don't think I could reach Philadelpia from here... unfortunately!

 

[baxtr]

Re: HELP! Our boat won't go!!!

if the bad cylinder is scored you do need to have it overbored at a machineshop....a marine machineshop. you can do just the bad cylinder without doing the rest. I did 2 cylinders on my 125 cost under 500 bucks and runs like new now. boring and honing (in wisconsin) 75 per hole, pistons rings wrist pin bearings 100 +/- gasket set 80 +/- needed tools are cheap too, borrow them and they are even cheaper

 

[maxum-mama]

Re: HELP! Our boat won't go!!!

Thanks for all the help! We'll see what we can do...

 

[zkimball]

Re: HELP! Our boat won't go!!!

I've seen a lot of older Mercs do this. You're out playing in the water and one of the carbs shuts down for some reason. The lubrication is in the fuel, that's what the oil is for. No fuel to the cylinder = no oil to the cylinder and you cook that pair. On the beach or in the driveway, it'll turn the revs right up, but not in the water and not at all for very long! Sorry! Z

 

[Nate3172]

Re: HELP! Our boat won't go!!!

Maxum, I'm in Washington State. Have rebuilt a number of force outboards and 2-stroke engines. I use to be a motorcycle mechanic. I live in Renton and work in Marysville. If you are anywhere close to my area I would be more than happy to give you and your husband a hand if needed.

 

[MercFan]

Re: HELP! Our boat won't go!!!

Edit: Nevermind. Is see you got low compression on a cylinder. Dang. Hope you come right with the repair and on the water quickly again! Good luck!

As suggested, just spin the prop by hand in neutral with the engine off. There should be no grinding noises. Just drain the lower unit's oil for the hell of it and check for anything foreign. Then I'd remove all the spark plugs, put the engine in reverse gear and spin the prop. It's be harder to turn, but not a hellova lot harder. You're now turning all the gears in the gearbox + the engine itself. You're just not turning it against compression.

If all those check out it could be the impact shook up your engine pretty good. So it could be unhitched links or if it's a carburettor engine it could be floats that got stuck in the float bowls or something similar.

 

[CharlieB]

Re: HELP! Our boat won't go!!!

Glad you found the problem, now, find the cause.

The stuck choke shouldl have flooded that cyl and killed the spark plug long before doing any damage to the rings or cyl.

Either case, the flywheel is going to come off in the course of repairs, pay particular attention to the flywheel key. Parking on a sandbar or anything else that rapidly stops an engine puts tremendous negative forces on the flywheel key, many times shearing it and the flywheel continues to rotate just a few degrees and advancing the ignition timing. Too far and the engine will not start, not so far and the engine will start but exhibit many of the symtoms you experienced, very poor performance, yet revs freely in neutral.

Advanced timing can destroy pistons and rings.